Improvement in furnace grate-bars



CARL HOFFMANN.

' Improvement in Furnace Grate Bars.

Pat ente d Jan. 23, 1872.

No.123,018. jy/

UNITED STATES PATENT QFFIGE.

CARL HOFFMANN, OF NEW YORK, N. Y.

IMPROVEMENT IN FURNACE GRATE-BARS.

Specification forming part of Letters Patent No. 123,018, dated January23, 1872.

nace Grate-Bars; and I do hereby declare the following to be a full,clear, and exact description thereof, which will enable those skilled inthe art to make and use the same, reference being had to theaccompanying drawing forming part of this specification, in which draw-1ng Figure 1 represents a side view of my invention. Fig. 2 is a plan ortop View of the same. Fig. 3 is a transverse section of the same in theplane as m, Fig. 1. Fig. 4. is a perspective View of the invention, partbeing broken away.

Similar letters indicate corresponding parts.

This invention consists in the arrangement of oblique ledges, beingchamfered off from both sides and cut down at the top in such a mannerthat by said ledges oblique air-channels are produced which connect witheach other by the depressions in the top edge of the body of the bar,and at the same time by the oblique position of the ledges a grateformed from my bars is capable of supporting comminuted coal orsaw-dust, or in fact the most inferior kinds of fuel which cannot beconsumed on grates of the ordinary construction.

. In the drawing, the letter A designates my grate-bar, which isprovided with a series of oblique ledges, a, projecting from both sidesof its body or web, I). The ledges are inclined at an angle of aboutforty-five degrees toward the upper surface of the grate-bar, as shownin Fig. 1; and those portions of the web b which are situated betweenthe several ledges are sharpened from both sides, as shown in Fig. 3,and they are cut down so as to form depressions, 0, between the ledges,as shown in Fig. 1.

When two or more of my grate-bars are placed side by side the adjoiningledges form oblique channels d, through which the air has free access tothe fuel spread on the grate, and at the same time the oblique positionof the ledges prevents the fuel from dropping through said channels. Thechannels (1, between the several grate-bars, are in communication witheach other by the depressions c in the top edge of the web.

011 a grate composed of my bars I am enabled to burn the most inferiorfuel, such as coal-dust, saw-dust, or even the refuse from locomotives,or from other steam-boilers having grates of the ordinary construction.In practice I use a fan-blower to force air between my grate, and asthis air strikes the ledges of the grate-bars it passes up through theoblique channels d, and is brought in intimate contact with almost everyparticle of the fuel spread on the grate, and a perfect combustion iseffected, while the fire goes down immediately the fan-blower isstopped, so that the formation of steam can be controlled with greataccuracy, and the danger of an explosion from scribed.

' CARL HOFFMANN.

Witnesses:

W. HAUFF, E. F. KASTENHUBER.

